We’ve already written several articles about AEMO flagging the possible need for early-morning direction (intervention) in the NSW region tomorrow morning, and a forecast LOR1 condition in play – both related (at least in part) to unplanned outages at three coal units:
1) An unplanned outage at MP2 that has already commenced; and
2) A looming unplanned outage at ER03 that looks set to commence coincident with the timing of the direction
3) Plus the longer unplanned outage at VP5 due to ‘turbine vibrations’.
Not specifically about System Strength but more generally about the forecast (relatively) tight supply-demand balance denoted in the forecast LOR1 condition for NSW for tomorrow evening (Thursday 25th September 2025), it’s worth flagging what’s visible in the ‘Constraint Sets’ widget, filtered to just constraint sets related to outages on the 330kV lines leading in from southern NSW into Sydney:
Note that there are two relevant constraint sets that might deliver pricing outcomes higher than what a more basic bid-stacking view would otherwise suggest, by delivering congestion in southern NSW and limiting the amount of generation that can actually reach the RRN (depending on bidding, supply of VRE and other parameters):
1) There’s the ‘N-AVMA_17’ constraint set:
(a) which we have seen before several times –
i. Such as on Tuesday 28th January 2025; and
ii. On Friday 7th February 2025.
(b) and which relates to an outage on the ‘Avon to Macarthur (17) 330kV line’ (more prior articles linked there).
2) There’s the ‘N-WGWA_X5’ constraint set:
(a) which we have not written about directly before
(b) but relates to an outage on the ‘Wagga to Walla Walla (6Y) 330kV line’
(c) But I do note that the constraint also relates to the X5 lines
So watch this space….
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